Which partition of my device is broken? I updated it to 5.0.3 and when it finished my kindle stucked and I could not boot into main again.

How did you "recover" mmcblk0p1? You cannot do that from fastboot (it is too big). You can boot to diags use a RUNME.sh script, or you can use fastboot to flash mmcblk0p2_ssh.img to diags and use an SSH shell, then copy mmcblk0p1.img to /dev/mmcblk0p1 (from RUNME.sh or at an SSH shell).

How did you "recover" mmcblk0p1? You cannot do that from fastboot (it is too big). You can boot to diags use a RUNME.sh script, or you can use fastboot to flash mmcblk0p2_ssh.img to diags and use an SSH shell, then copy mmcblk0p1.img to /dev/mmcblk0p1 (from RUNME.sh or at an SSH shell).

I will be busy for the next few days. Perhaps somebody here can provide a link to a main system linux kernel image (extracted from a backup of the first 32MB of /dev/mmcblk0, at offset 0x41000 as I recall -- and the length is in the flash header at the beginning of the kernel image).